Microsoft just released version 3.0 of their free Virtual Machine Servicing Tool (VMST). This version is the follow-up of version 2.1 which was released in December 2009 and is the result of the beta which started in May this year.
The VMST is a patch management solution which can be used to update stopped or saved state VM’s on a Hyper-V or Virtual Server 2005 R2 SP1 host . And also VM Templates, offline VM’s and offline Virtual Hard Disks(VHD) stored in the VM Library of System Center Virtual Machine Manager (SCVMM). In order to achieve this, the tool applies updates to the VHD using so called Servicing Jobs.
Servicing Jobs, which use Windows Powershell start the VM, update the VM and either shuts down the VM or brings the VM back into a saved state. Offline VHD’s are updated by mounting them to a running host and updating it using the Deployment Imaging Servicing and Management (DISM) tool.
VMST can leverage both System Center Configuration Manager (SCCM) 2007 SP1 and higher or Windows Server Update Services (WSUS) version 3.0 SP1 or higher to achieve this.
Changes in this update:
• Patching of offline virtual machines in a System Center Virtual Machine Manager (SCVMM) library
• Patching of stopped and saved state virtual machines on a host
• Patching of virtual machine templates
• Support for manual copy of update packages into offline virtual hard disks in a SCVMM library
• Support Hyper-V Live Migration (requires Windows Server 2008 R2 failover clusters)
The VMware counterpart for this tool is Update Manager, which was first released with VI 3.5.
Update: Unfortunately the Support for Hyper-V Live Migration feature didn’t make it in the final version of the VMST. As pointed out by Michel Lüscher.